Abstract:

In Wuerhe-Xiazijie Area，oil and gas have been discovered in ten formations of Permian，Triassic and Jurassic strata.According to the origins and sealing conditions，the reservoirs can be divided into six types，they are anticline reservoirs，fault block reservoirs，unconformity reservoirs，heavy oil sealing reservoirs，lithology-pinchout reservoirs and fault-lithologic reservoirs.Because of the multi-period tectonic movements，multi-period fault systems，many unconformities and connected sand bodies，which constitute the three-dimensional net migration systems，were formed.Sand bodies in middle and lower Triassic strata are extensively developed and best connected.Unconformities at the bottom of Jurassic strata，which have good layered structures，are good places for hydrocarbon migration and accumulation.Fault activities in Indo-Chinese epoch，which were in the same period with the hydrocarbon expulsions from source rocks，created the vertical migration pathways，and the fault activities decreased after the Indo-Chinese epoch when oil and gas were trapped in the lower wall of the faults.In terms of the sources of oil and gas，migration pathways and directions and the reservoir-forming periods，the accumulation models can be divided into four types：“一”- like accumulation models，“Y” -like accumulation models，“Z” -like accumulation models and “多”- like accumulation models.

Key words: Junggar Basin, hydrocarbon distribution, reservoir types, conducting system, accumulation model